Anhydrous monocarboxylic acid detergent compositions



United States PatentO 2,992,992 ANHYDROUS MONOCARBOXYLIC ACID DETERGENT COMPOSITIONS Leo P. 'Curtin, Cranbury, NJ. No Drawing. Filed Aug. 15, 1957, Ser. No. 678,453 12 Claims. (Cl. 252-109) This application is a continuation-in-part of my copending application Serial Number 468,158, filed November 10, 1954, and now abandoned.

This invention relates to detergent compositions in powder form, said compositions comprising substantial amounts of anhydrous, free mono-carboxylic acids having a solidification point of at least 30 C. and containing from 12 to 22 carbon atoms, the molecules of said acids containing an alkyl group having from 11 to 17 carbon atoms, said detergent compositions also containing sodium carbonate in proportion of at least one mole of carbonate to two moles of mono-carboxylic acid, said detergent composition also advantageously containing detergent builders selected from phosphates and polyphosphates of soda, sodium silicate, sodium salts of ethylenediaminetetr-aacetic acid, sodium sulfate and sodium carboxymethylcellulose, the components of said composition being intimately mixed, under anhydrous conditions, to form a detergent composition; all as is more fully hereinafter set forth and as claimed.

Potassium and ammonium salts may, under most conditions, replace the sodium salts listed above; also, sodium chloride may replace sodium sulfate as an additive.

The carboxylic acids of the present invention are obtainable from two sources, (a) the fatty acids obtained by hydrolysis of the naturally occurring fats and, (b) carboxyl-ic acids of synthetic origin.

The art of splitting the animal and vegetable fats into free acid and glycerol is more than a century old, is very well understood and is currently practiced on the large scale. The mixtures of the resulting fatty acids are recovered with very little accompanying water and this can be removed quickly by heating to a temperature above 100 C.

Lauric, myristic, palmitic and stearic acids have melting points ranging from 43 to 69 C. and all are suitable for use in the present invention. While oleic and linoleic acids are liquids at ordinary temperatures, they may be used in small amounts in connection with the saturated I acids named above, especially with palmitic and stearic acids.

The synthetic mono-carboxylic acids of the present invention are mono-esters of di-carboxylic acids containing from 2 to 4 carbon atoms which have been caused to react with suitable alcohols. The synthesis of such esters is not a part of the present invention. Such syntheses are, however, described in detail in my co-pending application, S.N. 468,158, above cited, and now abandoned, also, in my co-pending application S.N. 651,185.

The homogeneous mixtures of such mono-carboxylic acids with soda ash dissolve quickly when brought into contact with water, forming the expected detergent solutions.

The naturally occurring mono-carboxylic fatty acids and those of synthetic origin are compatible and may be used in mixture, in the present invention. The resulting de tergent is definitely more effective than one based on fatty acids, alone, and also produces much less suds. It may be used at a somewhat lower pH, 7.5 to 8, than is necessary with the fatty acid soaps.

The following examples of the invention are given for purposes of illustration, only:

2 Example 1 Percent Stearic acid 24 Pahnitic acid 36 Oleic acid 5 Soda ash 30 Sodium metasilicate, anhydrous 5 The materials of Example 1, intimately mixed, :form a strongly alkaline, heavy-duty laundry detergent powder.

The product of Example 2 is a mildly alkaline, generalpurpose washing powder.

Example 3 Percent Coconut oil acids 60 Soda ash 30 Tetrasodium pyrophosphate 8 Sodium carboxymethylcellulose 2 The product of Example 3 is suitable for dish-washing. The quality is slightly improved by removing the C and C8 acids.

Example 4 Percent Myristic acid 30 Mono-lauryl maleic acid ester,

(C H CH OCHCHCOOH) 30 Soda ash 30 Tetrasodium pyrophosphate 10 The product of Example 4 is an efiicient detergent powder which produces only a small amount of suds.

Example 5 1 Percent n-Dodecyl hydrogen maleate,

(C H CH OCO.CHCHCOOH) 2O Soda ash 5 Sodium sulfate, anhydrous 58 Sodium tripolyphosphate 15 Sodium carboxymethylcellulose 2 (C H CO.NH.CH OCO.CHCHCOOH) 4 Soda ash 8 Sodium sulfate, anhydrous 50, Sodium tripolyphosphate 20 Ethylenediaminetetraacetic acid, tetrasodium salt 2 The product of Example 6 forms a mildly alkaline, unusually efficient, general-purpose detergent with plenty of fine suds.

Example 7 This is the formula of Example 5, except that n-dodecyl hydrogen maleate is replaced by n-dodecyl hydrogen oxalate.

3 Example 8 This is the formula of Example 5, except that n-dodecyl hydrogen maleate is replaced by n-dodecyl hydrogen malonate.

Example 9 This is the formula of Example 5, except that n dodecyl hydrogen maleate is replaced 'by the corresponding fumarate.

Example 10 This is the formula of-Example 5, except that n-dodecyl hydrogen maleate is replaced by-n-dodecyl hydrogen succinate.

The products of Examples 7 to 10 resemble that of Example 5.

It will be observed that the fatty acids and the fatty alcohols derived therefromare important intermediates in the preparation of the mono-ester mono-carboxylic acids of the present invention. These materials are never pure but are mixtures. For example, myristic acid of commercial grade'may'contain or IO percent of lauric acid and an equal amount of palmitic acid. Commercial stearic acid may contain 50 percent of palmitic acid. It is necessary, therefore, to speak of solidification points rather than of melting points.

The production of a finely divided, homogeneous mixture of mono-carboxylic acid and soda ash is readily brought about. 'The chemical industry is well equipped with pulverizers, mullers, ball mills, etc. to make such a product. I prefer to pulverize the mono-'carboxylic acid and the soda ash'together until the desired degree of fineness and dispersion is attained, continuing the operation after adding such other additives as may be desired. Such builders or additives require only a reasonably good dispersion.

It will be evident that a continuous process may advantageously be used to produce the mono-carboxylic acid detergent composition. For example, at the starting point, soda ashand mono-carboxylic acid are charged in the proper proportions, detergent additives may be charged at an intermediate point and, at the discharge point, a continuous stream of the desired detergent composition emerges, ready for packaging.

The powdered detergent compositions above described have very good shelf life; 14'different formulations were allowed to stand for three years and were then found to be free-flowing powders, as good as when freshly made.

Ordinary soap powder dissolves much more slowly than the synthetic detergentpowders and this fact has helped .to increase the sale of the synthetic products. The powders of the present invention dissolve in water in one-half to one-fourth the time required by the soap powders, being comparable to the synthetic powders in this respect. When the carboxylic acid is 'of'the monoester type'above "described, complete solution 'takes place in 4 or 5 seconds.

The chief advantage of the mono-carboxylic acid detergent compositions is the extreme simplicity of their manufacture. With fatty acids produced by the nonalkaline hydrolysis offats, present practice is toconvert them to soaps by agitating with strong sodium hydroxide solution, the separation of the soap, its dehydration and conversion to soap powder being complicated and fairly expensive operations. In the present process, the anhydrous, solid fatty acid is ground with soda ash, with or without other additives, and this simple operation gives directly the detergent powder. The same procedure is used with the synthetic carboxylic acids. -When maleic anhydride is mono-'esterified with'dodecyl or other suitable alcohol, the reaction at 100 to 120 C. is'quantitative in 5 minutes, the reaction product, after solidifying, being ground with soda ash to forma detergent composition.

Other advantages of thepresentprocess will readily be apparent.

What I claim is:

1. As a new detergent composition, an anhydrous, freefiowing, quick-dissolving powder consisting essentially of from about 18 percent to about 88 percent of a finely divided, anhydrous monocarboxylic acid of solidification point at least as high as 30 C. in intimate mixture with finely divided, anhydrous sodium carbonate, said monocarboxylic acid being selected from the class consisting of saturated fatty acids of 12 to 18 carbon atoms and monocarboxylic acids which are monoesters of dicarboxylic acids having from 2 to 4 carbon atoms, said monoester monocarboxylic acid having in its molecule 14 to 22 carbon atoms and containing an alkyl groupof 12 to 17 carbon atoms, the sodium carbonate being present in amount of at least one mole for each two moles of monocarboxylic acid.

2. The detergent composition of claim 1 wherein a substantial amount from about 5 to about 75 percent, of a detergent builder selected from the class consisting of phosphates, polyphosphates, sulfates and silicates of soda and sodium carboxymethylcellulose is intimately mixed with the sodium carbonate-monocarboxylic acid mixture.

3. The detergent composition of claim 1 wherein fatty acid and monoester monocarboxylic acid areboth present.

4. The detergent composition of claim 1 wherein the sodium carbonate is soda ash.

5. As a new detergent composition, an anhydrous, freeflowing, quick-dissolving powder consisting essentially of from about 30 percent to about 65 percent of an anhydrous, finely divided, saturated C to C fatty acid in intimate mixture with finely divided, anhydrous sodium carbonate, the sodium carbonate being present in amount of at least one mole for each mole of saturated fatty acid.

6. As a new detergent composition, an anhydrous, freeflowing, quick-dissolving alkaline powder consisting essentially of from about 30percent to about 65 percent of an anhydrous, finely divided C to C saturated fatty acid in intimate mixture with finely divided, anhydrous sodium carbonate and finely divided, anhydrous sodium silicate, the sodium carbonate plus sodium silicate being present in amount of at least one mole for each mole of saturated fatty acid, the silicate being in amount equal to at least 5 percent of the carbonate.

7. As a new detergent composition, an anhydrous, freeflowing, quick-dissolving powder consisting essentially of from about 18 percent to about 88 percent of afinely divided, anhydrous monocarboxylic acid of solidfication point at-least as high as 30 C. in intimate mixture with finely divided, anhydrous sodium carbonate, said monocarboxylic acid being selected from the class'consisting of monocarboxylic acids which are monoesters of dicarboxylic acids having from 2 to 4 carbon atoms, said monoester monocarboxylic acid having in its molecule 14to 22 carbon atoms and containing an alkyl group of 12 to 17 carbon atoms, the sodium carbonate being present in amount of at least one mole for each two moles of monoester monocarboxylic acid.

8. A process for making an anhydrous detergent composition in powder form which comprises mixingfinely divided, anhydrous sodium carbonate and anhydrous, finely divided monocarboxylic acid of solidification point at least as high as 30 C. to form a homogeneous powder, said monocarboxylic acid being selected from the class consisting of saturated fatty acids of 12 to 18 carbon atoms and monocarboxylic acids which are monoesters of dicarboxylic acids having from 2 to 4 carbon atoms, said monoester nionocarboxylic acid having in its -molecule 14 to 22 carbon atoms and containing an alkyl group of 12 to 17 carbon atoms, the sodium carbonate being present in amount of at least one mole for each two moles of monocarboxylic acid, the resulting product being a free-flowing, quick-dissolving powder containing the sodium carbonate and the monocarboxylic acid in uncombined condition.

9. The process of claim 8 wherein a substantial amount, from about 5 to about 75 percent, of anhydrous, finely divided detergent builders selected from the class consisting of phosphates, polyphosphates, sulfates and silicates of soda and sodium carboxyrnethylcellulose are added to the mixture of monocarboxylic acid and anhydrous sodium carbonate.

10. A process for making an anhydrous detergent composition in powder form which comprises mixing finely divided, anhydrous sodium carbonate and finely divided, anhydrous C to C saturated fatty acid to form a homogeneous powder, the sodium carbonate being present in amount of at least one mole for each mole of saturated fatty acid, the resulting product being a freefiowing, quick-dissolving powder containing sodium carbonate and saturated fatty acid in uncombined condition.

11. A process for making an anhydrous alkaline detergent composition in powder form which comprises mixing finely divided, anhydrous sodium carbonate, and finely divided, anhydrous sodium silicate and finely divided, anhydrous C to C saturated fatty acid to form a homogeneous powder, the sodium carbonate plus sodium silicate being present in amount of at least one mole for each mole of saturated fatty acid, the silicate being in amount equal to at least 5 percent of the carbonate, the resulting product being a free-flowing, quickdissolving powder containing sodium carbonate, sodium silicate and saturated fatty acid in uncombined condition.

12. A process for making an anhydrous alkaline detergent composition in powder form which comprises mixing finely divided, anhydrous sodium carbonate and finely divided, anhydrous monocarboxylic acid of solidification point at least as high as 30 C. to form a homogeneous powder, the molecule of said monocarboxylic acid having from 14 to 22 carbon atoms and containing an alkyl group of 12 to 17 carbon atoms, said monocarboxylic acid being a monoester of a dicarboxylic acid having from 2 to 4 carbon atoms, the sodium carbonate being present in amount of at least one mole for each two moles of monocarboxylic acid, the resulting product being a free-flowing, quick-dissolving powder containing sodium carbonate and monoester monocarboxylic acid in uncom' bined condition.

References Cited in the file of this patent UNITED STATES PATENTS 2,243,054 Vail May 20, 1941 2,412,943 Bersworth Dec. 24, 1946 2,730,507 Bradford Jan. 10, 1956 FOREIGN PATENTS 10,680 Great Britain May 8, 1908 of 1907 473,220 Great Britain Oct. 8, 1937 772,538 France Oct. 31, 1934 OTHER REFERENCES Surface Active Agents, by Schwartz and Perry (1949), Interscience Pub. Inc., N.Y., pp. 232 and 235. 

1. AS A NEW DETERGENT COMPOSITION, AN ANHYDROUS, FREEFLOWING, QUICK-DISSOLVING POWDER CONSISTING ESSENTIALLY OF FROM ABOUT 18 PERCENT TO ABOUT 88 PERCENT OF A FINELY DIVIDED, ANHYDROUS MONOCARBOXYLIC ACID OF SOLIDIFICATION POINT AT LEAST AS HIGH AS 30*C. IN INTIMATE MIXTURE WITH FINELY DIVIDED, ANHYDROUS SODIUM CARBONATE, SAID MONOCARBOXYLIC ACID BEING SELECTED FROM THE CLASS CONSISTING OF SATURATED FATTY ACIDS OF 12 TO 18 CARBON ATOMS AND MONOCARBOXYLIC ACIDS WHICH ARE MONOESTERS OF DICARBOXYLIC ACIDS HAVING FROM 2 TO 4 CARBON ATOMS, SAID MONOESTER MONOCARBOXYLIC ACID HAVING IN ITS MOLECULE 14 TO 22 CARBON ATOMS AND CONTAINING AN ALKYL GROUP OF 12 TO 17 CARBON ATOMS, THE SODIUM CARBONATE BEING PRESENT IN AMOUNT OF AT LEAST ONE MOLE FOR EACH TWO MOLES OF MONOCARBOXYLIC ACID. 